Dual Boot Windows missing

rafoufouille Posted messages 9 Status Membre -  
mamiemando Posted messages 33540 Registration date   Status Modérateur Last intervention   -

I just set up dual boot on my desktop, so I had Windows on an NVMe SSD and I installed Ubuntu on a second NVMe SSD for dual boot. But when I restart my PC, the GRUB menu doesn't show up and Windows isn't detected...
However, in the Disks application in Ubuntu, Windows is indeed there on the other SSD.

How can I get Windows to appear at startup?

2 réponses

bonjour
 

Hello

"Installed Ubuntu on a second NVMe SSD in dual boot"

Was there really "in dual boot"?

And not just 2 installations on 2 drives?

Windows and Linux don’t name drives the same way, that’s one way to get it wrong.

Grub sometimes doesn’t install correctly or completely, and "repairing grub" can be the way to complete the installation. There are often tutorials on Linux to follow up.

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rafoufouille Posted messages 9 Status Membre
 

Yes, normally I installed it in dual boot. But maybe it made 2 installations on 2 disks so I'm not sure, it's the first time I'm doing a dual boot on two different disks.
And how do you do the "grub repair"?

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bonjour > rafoufouille Posted messages 9 Status Membre
 

Re

I'm walking on eggshells, never done that!

I don't know what you really did or the tutorials you followed.

The most appropriate tutorial seems to be this one, Malekal does them well.

https://www.malekal.com/grub-reparer-dual-boot-ubuntu-windows-10/

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brucine Posted messages 24411 Registration date   Status Membre Last intervention   4 105 > bonjour
 

Hello,

In the "Linux for Dummies" series, the behavior described is that Ubuntu was not installed in dual-boot but instead took over.

You can always try executing sudo update-grub so that the system automatically detects Windows; if that doesn't work, things are going to get complicated.

If it's just a matter of boot order, it will suffice, as suggested in the link in <3>, to edit efibootmanager using sudo efibootmgr -v and change the boot order.

The troubles will begin if the identifier corresponding to Windows does not appear at all; we might be able to restore the situation via Boot-Repair or rewrite the appropriate code, but I'll defer on that.

If the Ubuntu installation is "fresh" and there's nothing to lose, it might be quicker to reinstall Windows over itself with a Windows installation USB (thus preserving data), which will overwrite Grub, and from there delete the Linux installation, not forgetting to uninstall Grub and then reinstall Ubuntu correctly ("next to").

https://lecrabeinfo.net/desinstaller-ubuntu-linux-pc-dual-boot-windows.html

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jns55 > brucine Posted messages 24411 Registration date   Status Membre Last intervention  
 

Hello,

"We can always try to run sudo update-grub so that the system automatically detects Windows."

First, you need to reactivate os-prober, which is now disabled by default on Linux distributions that use grub 2.06 (and that's the case with Ubuntu 22.04).

To do this, you need to boot into Ubuntu and edit the file /etc/default/grub and set the value to false for the variable GRUB_DISABLE_OS_PROBER. 

sudo gedit /etc/default/grub

GRUB_DISABLE_OS_PROBER=false

You may need to add the line if it is not present in the file.

After saving the file, run the command sudo update-grub and if Windows is still there, it should finally appear in the menu. 

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mamiemando Posted messages 33540 Registration date   Status Modérateur Last intervention   7 927
 

Hello,

If Ubuntu is the only system seen by grub, it’s possible that grub does not display (it runs, but you don't see it appear on the screen, it immediately boots into Ubuntu). More details here.

As jns55 points out in #5, by default, grub no longer enables os-prober, which is responsible for detecting other operating systems (in your case, Windows) than the one from which you installed grub (in your case, Ubuntu). So by following the suggestion jns55 gives you in #5, you should be able to kill two birds with one stone: display grub and see Windows there.

Good luck

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